POS0929 VALUE OF LUNG ULTRASOUND FOR THE DETECTION OF INTERSTITIAL LUNG DISEASE IN PATIENTS WITH RHEUMATOID ARTHRITIS
Authors: R. Tanten, J. Marin, J. Zacariaz, J. Maritano, M. Fullana, R. N. Alvarado, J. Rosa
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Interstitial lung disease (ILD) is an extra-articular manifestation of rheumatoid arthritis (RA) associated with increased morbidity and mortality. High-resolution computed tomography (HRCT) is the gold standard for ILD diagnosis, but it has high cost and risk of ionizing radiation. Lung Ultrasound (LUS) is a non-invasive, low-cost, non-ionizing and easily performed diagnostic tool. <h3>Objectives</h3> To establish the diagnostic value of LUS in ILD in patients with RA, using chest HRCT as the gold standard. <h3>Methods</h3> A cross-sectional study was performed at the Hospital Italiano de Buenos Aires, Argentina. Consecutive patients with RA (ACR/EULAR-2010 criteria), who had a chest HRCT performed at least 12 months previous to inclusion.Demographic, clinical, laboratory and therapeutic data were recorded. Each patient underwent a LUS with a simplified examination (14 bilateral lung intercostal spaces -LIS-), with assessment of B-lines (BL) and pleural irregularities (PI). Additionally, a 6MWT was performed on each patient. For the diagnosis of ILD, HRCT was the gold-standard, taking as a threshold an extension of interstitial involvement ≥10%, scored by an expert lung specialist. ROC curves were made to test the ability of LUS findings (BL and PI), and 6 MWT, to discriminate patients with ILD. <h3>Results</h3> A total of 104 RA patients were included, 21,8 % with ILD, 82.7% (95% CI 74.0-89.4) were women, with a median age at diagnosis of RA of 57.5 years (IQR 47.3 -67.2) and a median disease duration of 8.7 years (IQR 3.3-15.8). 96.2% of patients (95% CI 90.5-98.9) were seropositive for rheumatoid factor (RF) and/or anti-citrullinated protein antibodies (ACPA), and median DAS28-ESR was 3.19 (IQR 2.6-4.6). Methotrexate had been used at some point of the disease in 94.2% patients (95% CI 87.9-97.8), and 46.2% (95% CI 36.3-56.2) were under bDMARD or tsDMARD treatment at inclusion. Patients with ILD were older at the time of RA diagnosis (64 vs 54 years, p=0.002) and had higher erythrocyte sedimentation rate (ERS) and C-reactive protein (CRP) (48 vs 29 mm/h and 5.9 vs 3 g/L p=0.002) than patients without ILD. In LUS, patients with ILD had more BL (median 26 vs. 1, p &lt;0.001), (Figure 1) and PI (median 12 vs. 4, p &lt;0.001) than patients without ILD.The diagnostic accuracy in ROC curves was: AUC 0.88 - 95% CI 0.78-0.93 for BL and AUC 0.82 - 95% CI 0.74-0.89 for PI (Figure 3 and 4). The best cut-off point for ILD detection was 8 BL and 7 PI.The performance of LUS was more sensitive than 6 MWT (Table 1). <h3>Conclusion</h3> The presence of 8 BL and/or 7 PI in the LUS showed an adequate diagnostic performance for ILD, with a good negative prognostic value. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Romina Tanten: None declared, Josefina Marin: None declared, Johana Zacariaz: None declared, Joaquin Maritano: None declared, Martin Fullana: None declared, Rodolfo Nicolas Alvarado: None declared, Javier Rosa Speakers bureau: Eli Lilly, AbbVie/Abbott, Bristol-Myers Squibb(BMS), Amgen, Novartis, Pfizer.